Electrically operated device



Patented sept. i9, 1939 UNITED STATES PATENT FFICI?.V

ELECTRICALLY OPERATED DEVICE aware 'Application March 9,

8 Claims.

My invention relates to electrically operated switches, and it has for its object the provision of a new and improved device of this type comprising a minimum number of parts by which a circuit carrying a power current or other work current may be opened and closed as desired as the result of opening or closing an auxiliary circuit. The present invention relates to constructions of the type shown in my prior Patent No.

l 2,051,622 of August 18, 1936, and involves certain improvements over the arrangement shown by that patent. A

It is one ofthe objects of my invention to provide an improved arrangement of the working u parts of the device whereby the alternating flux in the core parts adjacent tothe armature serves to overcome effectively any tendency for the maintainment of residual magnetism in the armature whereby an effective opening movement of the armature is assured following promptly l after the flow of induced current through the secondary coil has stopped. p

It is another object of my invention to provide an effective arrangement of the type specii fled in which the armature serves the double function of providing by itself a leakage: path for the desired amount of the flux and of operating the switch under the influence of such leakage ux.

' It is another object of my invention to provide an improved form and arrangement of armature 'and switching mechanism which shall be very strong and sturdy, which shall be very readily operable for .producing the desired results, and which shall be simple and so easily produced and assembled as to make the device inexpensive to manufacture.

It is another object of my invention to improve devices of this type in sundry details hereinafter I pointed out. The preferred means by which I have accomplished my several objects are illustrated in the drawing and are hereinafter specifically described. That which I believe to be new and desire to cover by Letters Patent is set forth 45 in the claims.

In the drawing- Fig. 1 is a top plan view of my improved device;

Fig. 2 is a vertical side view of the deviceof Fig. l, the parts being shown in operative position 50 for closing the circuits through the device;

` Fig. 3 is a horizontal sectional view taken at line 3 3 of Fig. 2, with thebody of the armature omitted from the showing and with the top frame plate of the core unit partially broalgen away for clearness of illustration;

1937, Serial. No. 129,854

.,Fig. 4 is a vertical sectional view taken at line 4--4 of Fig. 2, with the bottom portion of the coil member broken away; j

Fig. 5 is a vertical sectional view longitudinally through the removable switch unit;

Fig. 6 is a perspective View of the armature unit of the device; and Fig. 7 is a vertical sectional view taken at line I-1 of Fig. 3.

Referring now to the several iigures of the drawing, in which correspondingfparts are indicated by the same reference characters, I0 indicates a panel of insulation material upon which the core unit of my improved apparatus is mounted, such core unit in`- the arrangement shown comprising a bottom frame plate II of non-magnetic material, a laminated core body I2 of magnetic metal, and a top frame plate I3 of non-magnetic material, all connected together by a plurality of rivets Il, the unit being secured to the panel IIl by means of screws I5 passing through lugs I6 formed on the bottom frame plate II.

As is best shown in Fig. 3, the core body I2 comprises two end bar portions II and I8 connected by means of side bar portions I9 and 2U, with a central winding bar portion 2I interposed between oppositely located notches in the inner faces of the end bar portions, such central bar portion 2| having a primary coil 22 and a secondary coil 23 mounted thereon in spaced relation to each other. By this construction, a double loop arrangement is provided for the core, with the central bar portion 2I forming a part of each of the loops, and with each of the loops including one of the side bar. portions therein. The frame plates I I and I3 are cut outy at their center portions to provide end bars and sidebars, with lugs 24 formed on said plates II and I3 on the side bar portions thereof and extending between the coils for holding them in the desired spaced relation to each other. Leads 25 are provided for feeding alternating current to the primary coil 22, and leads 26 for connecting the secondary coil 23 into a work circuit.

On the top face of the core unit, I have pivotally mounted an armature 21 upon a pivot pin 28 secured between upright arms 29 rising from the top frame plate I3 of the core unit. The armature in the arrangement shown comprises a laminated body portion 30 of magnetic material in the form of a yoke, extending from the pivot pin. 28 toward the right in Fig. 2 over and about the upper portion of the secondary coil 23 so as to jhave its free end at the right located in position to engage the intermediate portion of the central core bar 2| between the two coils 22 and 23 when the armature is swung to the limit of its motion in clockwise direction in said gure. In the construction illustrated, the armature has a frame member 3I of non-magnetic metal bent into the form of a U secured about the body portion with its intermediate web portion in spaced relation to the end of thebody, as is best shown in Fig. 6. Legs 32 carried by the U member extend below the body portion 3D of the armature for limiting the swinging movement of the armature as hereinafter described. The pole piece of the armature at thel right in the drawing is provided with a shading coil 33 of conductor metal extending about a portion of the iron making up such pole piece. The laminated plates making up the body 30 of the armature are formed in the arrangement shown of standard transformer steel without any special annealing process thereon preparatory to its use.

As is best shown in Fig. 2, the armature is positioned in slightly spaced relation to the core body I2 at the left so as to provide an air gap at 34 between the armature and the end bar I8 of the core. A spring 35 connected at its upper end with the frame member 3| of the armature unit and at its lower end with a lug 36 formed on the bottom frame plate II of the core unit serves normally to hold the armature at the limit of its swinging movement away from the core, the legs 32 of the armature unit serving by engagement with notched portions of the lug 36 to limit the movement of the armature away from the core.

The improved switching means of my device comprises a switchunit 31 (see Fig. 5) secured in position on the armature as shown in Fig. 2. This unit comprises a mounting block 38 of insulation material in the form of an angle piece, the horizontal arm of which is in the form of an inverted channel so as to embrace the armature unit snugly, being held in position on the armature by means of screws 39 extending through the vertical arm of the mounting block and engaging screw threaded openings 40 in the armature frame member 3 I. As is best shown in Fig. 4, this block 38 extends some little distance at both sides of the armature for the reception of the switch parts as hereinafter described.

As is best shown in Fig. 5, a thin strip of conductor metal bent into angular form to provide a horizontal arm 4I and a downwardly extending A arm 42 is mounted on the block 38 at each side of the unit, the intermediate portion oi' each of .said strips being located in a slit 43 which is located in approximate alignment withthe inner face of the downwardly extending arm of the mounting block. About the mounting block at each side of the block I have provided a second strip of metal bent into angular form to provide a horizontal arm 44 and a downwardly extending arm 45, the downwardly extending arm 45 being bent into position normally to engage the outer face of the switch arm 42 at a point spaced downwardly from the mounting block. Inside of the angle of the mounting block at each side of the block, I have provided a third strip of metal bent into angular form to provide a short vertical arm portion 46 and a horizontal arm portion 41, the horizontal arm portion 41 being bent into position normally to engage the bottom face of the switch arm 4I at a point in spaced relation to the mounting block. The three angular parts of metal as described are rigidly connected together and to the mounting block at opposite sides thereof at their vertically extending portions by a rivet 48 and at their horizontally extending portions by a rivet 49, thev arrangement being such that the parts strongly reinforce each other so as to give the switch unit a high degree of strength so as to be capable of withstanding long continued hard use. v

The switching means arranged to cooperate with the switch unit 31 comprises a metallic post 5U at each side of the structure, having a contact member 5I and a binding screw 52 thereon, the contact member 5I being-in position to engage a contact member 53 carried by the switch arm 4I at that side of the device. A metallic post 54 is also provided at each side of the device, each of the posts 54 being provided with a contact member 55 and a binding screw 56, the contact member 55 at each side of the device being in position to engage a contact member 51 carried by the switch arm 42 at that side of the device. The arrangement is such that, when the armature is held by the spring 35 swung to the limit of its motion in counterclockwise direction in Fig. 2, the contacts 53 stand in spaced relation to the contacts 5I and the contacts 51 stand in spaced relation to the contacts 55, so as to open the circuit at two points between the binding posts 52 and 56 at each side of the device. When, however, the armature is swung to the limit of its movement in clockwise direction against the action of the spring 35 into the position as shown in said Fig. 2, the circuit between the binding screws 52 and 56 is closed at each side of the device, with the contact members .at each point pressed firmly together for assuring an effective circuit through the parts. In the eiective switch closing position of the parts, the switch arm 4I stands in slightly spaced relation to the arm 41 of the switch unit, and the switch arm 42 stands in slightly spaced relation to the arm 45, as is clearly shown in Fig. 2, the movement of the arms 4I andA 42 out of engagement with the arms 41 and 45 respectively being eiectedagainst the force of the resiliency of said arms 4I and 42. The movement of the armature into engagement with the core bar 2I is thus cushioned so as to cut down the noise and to eliminate the shock so far as possible.

In operation, the coil 22 is connected with a source of alternating current so as to cause an exciting current to flow therethrough While the circuit through the secondary coil 23 is open. Such exciting current establishes an alternating flux through the double core loop, without any appreciable effect, however, upon the armature 29 which is normally being held-by the spring 35 yieldingly in its raised position. When under these conditions the circuit is completed through the secondary coil 23 so as to permit the establishment of an induced current through the coil 23, a portion of the alternating ilux is diverted from the part of the winding bar 2| upon which the coil 23 is mounted and is caused to flow through the armature 3l without threading the secondary coil. By reason of the passage of a portion of the flux through the armature while the circuit through the secondary coil is closed, the armature is drawn downwardly by magnetic attraction against the action of the spring 35.' 'I'his movement of the armature toward the core serves to bring the parts into switch closing position as illustrated in Fig. 1 and serves also to increase substantially the eiectiveness of the armature as a shunt means so as to prevent the flow of excessive current through the secondary coil. By reason of the provision of the shading coil Il, the armature is caused to remain in its lowered switch closing position continuously as long as the circuit through the secondary coil remains closed, this result being attained without any vibration or chattering of the armature. Promptly upon the opening oi the circuit through the secondary coil 23, the passage of the ux through the armature ceases and the spring serves to swing the amature in counter-clockwise direction from the position as shownl in Fig. 2, so as to open the circuit between the contacts 5I and 53 and between the contacts 55 and 51.

In the opening movement of the switch unit when actuated by the armature as above described, the, arm I1 which is comparatively stiil is brought 4into operative engagement with the switch arm 4l for applying pressure upwardly thereon for moving the contact I3 out o! engagement with the contact 5l. In like manner the arm engages the switch arm l2 and presses it toward the right in Fig. 2 for moving the contact- 51 out of engagement with the contact 55. When the circuit through the secondary coil 23 is broken, even if the berak should come at maximum flux density in the armature, the continued alternating flux through the core parts adjacent to the armature has a demagnetizing eiIect by which the maintainment' of any residual magnetism in the armature is prevented.

By the use of my improved construction, in which the parts are simple in form and are easily produced and easily assembled, I am enabled to provide an effective structure at a comparatively4 low cost, the moving parts being adapted to mutually reinforce each other so as to provide a high degree of strength and sturdiness in proportion to the amount of material required for the manufacture of the device. My improved arrangement by which the maintalnment of residual magnetism in the armature is protected against enables my device to operate during long periods without any deterioration or any reduction in its elllciency.' It is to be understood that I prefer to employ the form of apparatus as shown in my drawing and as above described but that my invention is not limited thereto except so far as it may be so limited by the narrower claims.

I claim:

1. In a device of the type described, the combination of a core in the form of a closed loop comprising a central core bar and auxiliary core means connecting the ends of the bar providing a double return path for magnetic iiux set up in the bar, primary and secondary coils mounted on said core bai in spaced relation to each other thereon, and an armature in the form of a yoke made of magnetic material resiliently mounted adjacent to the core so as to be movable toward and away from said core loop with its legs embracing one of said coils and adapted by itself when moved toward the loop with the circuit through the secondary coil eiectually closed to shunt such portion of the magnetic ux from the portion of the loop upon which the secondary coil is mounted as to prevent the ilow of excessive current through the secondary coil.

2. In a device of the type described, the combination of a core in the form of a closed loop comprising a central core bar and auxiliary core means connecting the ends of the bar providing a double return path for magnetic ilux set up in the ture made of magnetic material yieldingiy mounted'on one portion of the core loop between the coils so as to swing about a pivot toward and away from the opposite portion of the core loop between the coils and adapted by itself when moved toward the loop, with the circuit through the secondary coil eiIectually closed, to shunt such a portion of the magnetic iiux from the portion of the loop upon which the secondary coil is mounted as to prevent the flow of excessive cur# rent through the secondarycoil.

g 3. In a device of the type described, the combination of a core in the'form of a closed loop comprising a central core bar and auxiliary core means connecting the ends of the bar providing a double return path for magnetic ilux set up in the bar, primary and secondary coils mounted on said core bar in spaced relation thereon, an armature in the form of a yoke made of magnetic material pivotally mounted on said auxiliary core means with an air gap between the yoke and the core and movable toward and away from the portion of the core bar between the coils and adapted by itself when moved toward the loop, with the circuit through the secondary coil eflectually closed, to shunt a portion of the magnetic flux from the portion of the loop upon which the secondary coil is mounted, and yielding means tending normally to hold the armature swung in the direction away from the core.

4. In a device of the type described, the combination of a core in the form of a closed loop comprising a central core bar and auxiliary core means connecting the ends of the bar providing a double return path for magnetic ilux set up in the bar, primary and secondary coils mounted on said core bar in spaced relation to each other thereon, and an armature of magnetic material pivotally mounted at one end closely adjacent to the core at one end of the secondary coil and extending normally into closely spaced relation to the core at the opposite end of the secondary coil and adapted when the circuit through the secondary coil is eiectually closed to shunt a portion of the magnetic ux from the portion of the loop upon which the secondary coil is mounted whereby the armature is moved by magnetic attraction toward the core.

5. In a device of the typedescribed, the combination of a core in the form of a closed loop comprising a central core bar and auxiliary core means connecting the ends of the bar providing a double return path for magnetic flux set up in the bar, primary and secondary coils mounted on said core bar in spaced relation thereon, an armature of magnetic material pivotally mounted at one end adjacent to said core loop with an air gap between the armature and the core and arranged in position to move toward and away from the opposite portion of the core loop and adapted by itself, when the circuit through the secondary coil is effectually closed, to shunt a portion of the magnetic iiux from the portion of the loop upon which the secondary coil is mounted whereby the armature is moved by magnetic attraction toward the core, yielding means adapted normally to hold the armature moved away from the core, and a resilient metal arm carried by the armature in position to be flexed slightly so as to cushion the movement of the armature toward the core when the armature is actuated by the passage of iiux therethrough.

6. In a device of the type described, the combination of a core in the form of a closed loop comprising a central. core bar and auxiliary core means connecting the ends of the bar providing a double return path for magnetic dus: set up in the bar, primary and secondary coils mounted on said core bar in spaced relation thereon, an armature of magnetic material pivotally mounted at one end adjacent to said core loop with an air gap between the armature and the core and arranged in position to move toward and away from the opposite portion of the core loop and adapted by itself, when the circuit through the secondary coil is efectually closed, to shunt a portion of the magnetic ux from the portion oi the loop upon which the secondary coil is mounted whereby the armature is moved by magnetic attraction toward the core, yielding means adapted normally to hold the armature moved away from the core, a resilient metal arm projecting horizontally from the armature, and a second resilient metal arm projecting downwardly from the armature, both of said arms being in position to be flexed slightly by engagement with other parts so as to cushion the movement of the armature toward the core when the armature is actuated by flux therethrough.

'7. In a device of the type described, the combination of an armature in the form of a yoke of magnetic material, a mounting block oi insulation in the form of an angle piece secured about one of the upper corners of the armature, a thin strip of conductor metal bent into angular form and mounted on said mounting block with one arm extending horizontally and the other arm extending downwardly irom the block, a second strip of metal bent into angular form about said mounting block with one arm portion extending airfares downwardly in position to engage the downwardly extending arm portion of said first named strip, a third strip of metal bent into angular form and located inside oi the angle of said mounting block with a horizontal arm portion in position to con tact the horizontal arm portion of said first named strip, and means for securing said four angular parts firmly together at both their horizontal and their vertical portions.

8. In a device of the type described, the com-` bination of an armature in the form of a yoke of magnetic material, a block of insulation in the form of an angle piece secured about one of the upper corners of the armature with a vertical slit therethrough in approximate alignment with the inner face of the downwardly extending arm of the mounting block, a thin strip of conductor metal bent into angular 'form and mounted on said mounting block in said slit with one arm extending horizontally and the other arm extending downwardly from the block, a second metal strip bent into angular form about said mounting block and on top of the horizontal arm of said first named strip and' engaging the outside face of the downwardly extending arm of said iirst named strip below the block, a third metal strip bent into angular form inside of said mounting block and on the inner face of the downwardly extending arm of said first named strip and engaging the bottom face of the horizontal arm of said first named strip in spaced relation to said block, and means for securing said four angular parts iirmly together at both their horizontal and vertical portions.

JGSEPH G. SOLA. 

